Impulse transmitter



May 31, 1932. w, GQFF 1,860,535

IMPULSE TRANSMITTER Filed June 9, 1931 2 Sheets-Sheet 2 lNl/E' N TOR ATTORNEY Patented May 31, 1932 UNITED STA ES.

PATENT Price HAROLD-W. GOFF, OF. GREAT NECK, NEW=YOBK, .A SSIG-NOR TOBELL TELEPHONE LAB- ORATQRIES,INCORPORATED, OF NEW YORK, N. Y., A. CORPORATION OF NEW YORK IMPULSE mnalvsivurrnn I Application filed .Tune 9, 1931. Seri'a1No.v543,071. I

This invention relates to impulse transmitters and particularly tolcalling dialsof the type commonly employed in automatic and semi-automatic telephone systems. I

6 In the art of automatic telephony the switching operations required in establishing telephone connections must necessarily be performed in a definite predetermined sein the dialstructure whereby a certain time n so interval is introduced between the timean operator starts to set up a connection and the time when dial pulses are" actually transmitted to actuate the automaticv switches. i

V Heretofclre, attempts have been made to provide thenecessary time interval by pro viding mechanical means which caused the pulsing springs of the telephone dial tobe moved clear of the pulsing cam for a short period of time before the rotation of the pulsmg cam become effective in actuating the pulsing springs. Such attempts havebeen characterized by the use of friction cams and other similar mechanisms which resulted-in somewhat complicated and expensive dialing devices, w

It is accordingly the object of thisginvention to provide an improved type of impulse transmitter which is mechanically positive in operation, simple in construction and which imposes no extra load on the dial during pulsing in introducing the necessary time interval prior to the 'transmission of pulses. I t

This object is attained in accordance with a feature of the invention by the "provision of an auxiliary short-circuiting spring which,

is controlled jointly, through the medium of a pivoted -elen1ent, by the main drive shaft and the pulsing cam shaft to maintain, the pulsing springs shortf-circuited during "the wind-up of the dial and for one complete rev olution of the'pulsing cam after the dial has been released.

. Theinvention will be readily understood from the following detailed description made with referenceto the accompanying draw ings, in which l Fig. 1 is anenlarged bottom plan View of a telephone dial embodying the features of this invention;

F ig. 2 is an enlarged partial fragmentary view of the pivoting member in oneof its stages of operation;

' Fig. 3-is a section takenalong the line 33 of -Fig.'"l looking in the direction of the arrows; I 7 Fig. 4 is an enlarged internal plan view of the dial operating mechanism; and I 1 Fig.5. is an exploded perspective of the means employed for locking the dial number plate in position.

- The dial casing lO is a die-casting provided with the/necessary pads and projections for mounting the various dial elements as willhereinafter'appear. ,A main drive shaft 11, housed in a centrally located sleeve of the casing 10, is provided at one end with a thread 12'which accommodates a nut 13 for theflpurpose ofsecuring the finger wheel 14 in place, the finger wheel being provided with a substantially rectangular slot which fits over a correspondingly shaped shoulderportion 15 of themain shaft 11. Theother end of the shaft 11 fits into the element 16 and is securedthereto in any suitable manner. A I main co l spring 17 has one end secured to the base ofthe casing 10 and its other end made fast to the element 16 so that when the shaft llis rotated the coilispring is wound up, the

casing lObein'g stationary.

Interposed between the finger wheel 14 and the shoulder 17*and staked to the shaft 11 is a ring-shaped element 18 provided with an integral, depending L-shaped bracket which supports a pin 19 which is screwed into a pawl 20, the-pin being rotatably mounted in the bracket. A coil spring 21 is'wound about the pin 19 as shown in Fig. 8, having one end secured to thepinand the other end maintain the pawl 20 in constant engagement with the ratchet 22. 2

The ratchet 22 is in reality a collar r0- tatably mounted on the centrally located sleeve of the casing 10, provided at its upper end with a series of ratchet teeth which are adapted to be engaged by the pawl 20, as will appear hereinafter.

A gear wheel 23 is staked to the lower end of the ratchet element 22, rotates therewith and meshes with a pinion gear 24 which is mounted on the pulsing shaft 25 rotatably housed in a depending sleeve portion of the casing 10. Immediately below the pinion gear 24, a worm wheel 26 is mounted on the shaft 25 which .meshes with the worm 27 which constitutes a part of a well known type of governor generally indicated by the numeral 28. A single lobe pulsing cam 29 is mounted on the end of the shaft 25 and is located, with respect to pulsing spring 60, in such a position as to successively actuate it upon the rotation of the cam.

A finger stop 30 mounted on a padof the casing 10 by means of screw 31 is provided with an internally projecting piece 32, clearly indicatedin Figs. 3, 4 and 5. A bridge member 33 is secured to the casing 10 by means of screws 34 and 35 (Fig. 4) and is provided with a projecting piece 36 corresponding. to and oppositely disposed to the finger wheel projection 32. The projections 32 and 36 serve to maintain the clam ing rin 37 in position, the depending resilient spring fingers 38 and 39 of the ring 37 being adapted to he slipped under the elements 32 and 36 respectively. The spring member 38 is so formed that, when the elements 38 and 39 are placed under the projections 32 and 36 respectively, and the ring 37 turned slightly, the ring becomes locked in position. The ring 37 serves to maintain the number plate 40 in position, the outer periphery of the plate resting on a circular shoulder portion of the casing 10.

A card holder generally indicated by the numeral 41 is provided for the purpose of displaying a card upon which a telephone number or other necessary information may be printed.

Particular reference is now made to Fig. 1. The base of the casing 10 is provided with two projecting pads 42 and 43 to which is secured, by means of screws 44 and 45, the

- bracket 46 which serves as a support for the governor shaft 47. A spring pile-up generally indicated at48 is also mounted on the underside of the casing 10.

Pivotally supported upon the casing 10 at 50 is a bracket 51 provided with two extensions 53 and 58 and supporting an insulating stud 52 which engages a hump on the auxiliary spring 56 and maintains it normally in contact with one of the pulsing springs 57. The projection 53 is normally engaged by the rojection 54 of the element 55 which is rigidly secured to the drive shaft 11, for the purpose of maintaining spring 56 in engagement with the common spring member 57 as mentioned above. The other projection 58 is so positioned as to be in the line of travel of the projection 59 which is immovably secured to the pulsing shaft 25. The purpose of the pivoted member 51 and its action upon spring 56 will appear from the following description of the operation of the dial.

As the functioning of the various elements which constitute a telephone dial are well known, the general operation of applicants device will be described briefly, though the parts which directly concern applicants invention will pe discussed fully.

The shaft 11 rotates with the finger wheel when the latter is actuated by an operator and causes the main spring 17 to be tensioned. The element 18 and its associated pawl 20 rotates with the shaft 11, the pawl 20 riding over the teeth in the ratchet member 22. A spring pawl 70, shown in Fig. 4,

revents the dial mechanism from turning ackwards during the setting of the dial. When the finger wheel 14 is released the shaft 11 and the elements'secured thereto are returned to normal by virtue of the unwinding of the coil spring 17. The pawl 20 engages with a tooth in the ratchet 22 causing the latter and the gear wheel 23 to be rotated. The gear wheel 23, by virtue of its meshing with pinion gear 24 causes the shaft 25 to rotate and the pulsing cam 29 being secured to the shaft 25, rotates correspondingly. The governor mechanism 28 is also actuated by means of worm wheel 26 and worm 27 to regulate the return s ed of the dial. During the rotation of tie shaft 25 the cam 29 repeatedly engages the end of spring 60 and repeatedly breaks contact between it and sprin 57 to effect the transmission of a set of pa ses corresponding to the setting of the finger wheel.

Referring now to Fig. 1, when the drive shaft 11 rotates from its normal position the element 55 secured thereto rotates correspondingly and the projection 54 is disengaged from the projection 53 of the pivot 51.

When the fingerwheel is released and the 1 dial mechanism functions to cause the rot-ation of the pulsing cam 29, the latter, upon its first rotation, actuates the pulsing spring 60, but no pulse is actually transmitted due to the fact that spring 56vis still in engagepulsing ment with spring ,57 which effects a short circuit of the pulsing springs .57 and 60. After the first actuation of the pulsing spring 60 by the cam29 the projection 59 secured to the shaft :25 of the pulsing cam engages the projection 58, causingthe member 51 to pivot about its axis 50, whereupon the stud 52 is moved ofi' the hump of spring 56. This action permits spring 56-to move away from spring 57 under its own tension. This condi tion is clearly shown in Fig. 2.

The disengagement of spring 56 from spring 57 removes the short circuit from the pulsing springs, so that every revolution of the cam 29 afterthe first one, is eiiective in transmitting a pulse, the first pulse having been voided by the short circuit of the ulsing springs efiected by the engagement 0 spring 56 with spring v57.

When the shaft 11 reaches its normal position the projection 54 of element. 55 again engages projection 53 to cause the closure of contact springs 56 and 57.

\Vhat is claimed is:

1. In an impulse transmitter, a pair of normally short-'circuited pulsing springs, a

pulsing cam for successively actuating said springs, means for actuating said pulsing cam and means actuated after the first interruption'of said pulsing springs by said cam for removing the short circuit from' said-pulsing springs.

2. In an impulse transmitter, a pair of normally SllOIlS-CllCllltGCl pulsing springs, a

pulsing cam for successively actuating said pulsing springs, means actuated after the first interruption ofsaid pulsing springs by said cam for removing the short circuit from said pulsing springs, and means efiective after the last interruption of said pulsing springs by said cam forreestablishing the short circuit about said pulsing springs 3. In an impulse transmitter, a pair of pulsingsprings, an auxiliary spring nor mally short-circuiting said pulsing springs, means for successively interruptin said pulsing springs,and means actuated after the first interruption of said pulsing'springs'for actuating said auxiliary'spring to remove the short circuit from said pulsing springs.

4. In an impulse transmitter, a pair of pulsing springs, an auxiliary spring normally short-circuiting said pulsing springs, means for successlvely interrupting said pulsing springs, means actuated after the first interruption of said pulsing springsfor actuatmg said auxiliary sprlng to remove the 7 short circuit from said pulsing springs, and means effective after the last interruption of said pulsing springs for reactuating said auxiliary spring to reestablish the short circuit about said pulsing springs.

5. In an impulse transmitter, a rotatable dial, a drive shaft upon which said rotatable dial is mounted, a pair of normally shortci'rcuited pulsing springs,a pulsing cam rotatably coupled to said drive shaft andadapt ed to successively: interrupt said pulsing springs uponthe release of said rotatable'dial, and means intermediate said drive shaft and said pulsing cam for maintaining the short circuit about said pulsing springs during wind-up of'said rotatable dial andremoving it after the first interruption of said pulsing of and reestablishing it after the last-inten ruption thereof. V

V 7. In an impulse transmitter, apair of pulsing springs, an auxiliary ,springnormally in contact with one'of said pulsing sprlngs, means for successively interrupting said pulsing springs to transmit a series of impulses, mechanical means controlling the op? eration of said auxiliary spring, and means for alternately actuating said mechanical means to remove said auxiliary spring from engagement with-its associated pulsing spring after the first interruption thereof and mov-' ing it into engagement with the same one of said pulsing springs after the last interruption thereof."

8. In an impulse transmitter, a pair of nor mally short-circuited pulsing springs, a piv-- oted member for establishing and removing the short circuit from said pulsing springs, a 7

drive shaft, a cam shaft driven by said drive shaft, a cam mounted on said cam shaft and adapted tosuccessivelyinterrupt said pulsing springs upon the actuation of said drive shaft, means mounted on said cam-shaft for actuating said pivoted member after the first interruption of said pulsing springsto remove the short circuit therefrom, and means mounted on said drive shaft for reactuating said pivoted member after the lastinterruption of said pulsing springs to reestablish the short circuit.

9. In" an impulse transmitter, a pair of. pulsing springs normally in engagement with each other, an'auxiliary spring normally in contact with one of said pulsing springs and in permanent electrical association withthe other of said pulsing springs, means for successively interrupting said pulsing springs, and means actuated'by said last mentioned means for removing said auxiliary spring from engagement with one of said pulsing springs after the first interruption of said pulsing springs.

. 10. In an impulse transmitter, a pair of ulsing springs, an auxiliary spring effecting a short circuit about said pair of pulsing springs, means for successively interrupting said pulsing springs, and means actuated by said last mentioned means for actuating said auxiliary spring to remove the short circuit from said pulsing spring after the first interruption thereof.

11. In an impulse transmitter, a pair of pulsing springs, an auxiliary spring efi'ecting a short circuit about said pair of pulsing springs, a pulsing cam for successively interrupting said pulsing springs, means for actuating said pulsing cam, and means effective after the first interruption of said pulsing springs by said cam for actuating said auxiliary spring to remove the short circuit therefrom. y

In witness whereof, I hereunto subscribe my name, this 3d day of June 1931.

HAROLD W. GOFF. 

